The annual aerial spring inventory of antelope was conducted from April through June, 2000. From these survey data, the July population of antelope in South Dakota was estimated to be 33,322 and the average doe:fawn ratio was 100:94.

The annual aerial spring inventory of antelope was conducted from April through June, 2001. From these survey data, the July population of antelope in South Dakota was estimated to be 33,420 and the average doe:fawn ratio was 100:86.

The annual aerial spring inventory of antelope was conducted from April through June, 2003. From these survey data, the July population of antelope in South Dakota was estimated to be 40,788 and the average doe:fawn ratio was 100:85.

The annual aerial spring inventory of antelope was conducted from April through June, 2002. From these survey data, the July population of antelope in South Dakota was estimated to be 29,258 and the average doe:fawn ratio was 100:83.

The annual aerial spring inventory of antelope was conducted during May, June, and July, 1978. From this survey data, the July population of antelope for western South Dakota was estimated to be 28,427, and the doe:kid ratio was 100:82.